Adipocyte-derived collagen VI affects early mammary tumor progression in vivo, demonstrating a critical interaction in the tumor/stroma microenvironment
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Summary
This summary is machine-generated.Adipocytes secrete Collagen VI, crucial for breast cancer growth. This protein fragment signals through specific receptors, activating pathways that promote tumor cell survival and proliferation.
Area Of Science
- Oncology
- Cell Biology
- Biochemistry
Background
- Adipocyte-derived factors influence breast cancer progression.
- Specific adipocyte factors critical for tumor growth remain unidentified.
- Collagen VI is highly expressed in adipocytes.
Purpose Of The Study
- To identify critical adipocyte-derived factors in breast cancer.
- To elucidate the role of Collagen VI in mammary tumor growth.
- To investigate the signaling pathways involved in Collagen VI-mediated tumor promotion.
Main Methods
- Utilized the MMTV-PyMT mouse mammary cancer model.
- Generated Collagen VI-deficient mice (Collagen VI-/-).
- Analyzed tumor growth, hyperplasia, and cell signaling pathways (Akt, beta-catenin, cyclin D1).
- Investigated the effects of Collagen VI fragments on MCF-7 cells in vitro.
Main Results
- Collagen VI deficiency significantly reduced hyperplasia and primary tumor growth in MMTV-PyMT mice.
- Collagen VI signaling involves the NG2 receptor on malignant ductal epithelial cells.
- Activation of Akt, beta-catenin, and stabilization of cyclin D1 were observed.
- Upregulated carboxyterminal domain of collagen VIalpha3 in human and murine breast cancer lesions.
- This fragment promoted growth of MCF-7 cells in vitro.
Conclusions
- Adipocytes significantly contribute to early-stage tumor growth via Collagen VI.
- Collagen VI shapes the tumor microenvironment, promoting cancer cell survival and proliferation.
- The carboxyterminal fragment of Collagen VI is a key mediator of these effects.